We propose to acquire a high-performance hybrid microCT/microSPECT imaging system to setup an animal imaging facility for both structural and functional imaging. With this instrument, we will establish at The University of Chicago a routine SPECT and CT imaging capabilities for quantitative measurements of important anatomic and physiological parameters in animal studies, and thus greatly enable and enhance the research of a number of NIH funded investigators, and offer pilot study opportunities to many others. At The University of Chicago, we currently have NIH funded Cancer Research Center Core Facilities of MRI/MRS and optical imaging, a unique resource center of EPRI (electron paramagnetic resonance imaging), also funded by NIH, and imaging physics and instrumentation laboratories that have designed and built several prototype systems for single-photon, PET, and CT imaging. We are establishing a collection of core facilities with commercial systems that can be placed in a user-friendly environment for routine applications to in vivo small animal imaging. This proposed purchase of a hybrid microCT/microSPECT imaging system will be an essential step toward that goal. Major users include investigators from the following NIH-funded research: 1. Quantitative imaging for assessing tissue injuries and cell repairs; 2. SPECT/CT imaging for investigation of selective estrogen receptor modulators (SERMs); 3. Novel reconstruction methods for improving quantitative measurements and image quality; 4. Molecular bases of bone formation and bone tumor development 5. SPECT/CT imaging for evaluation of radio-/chemo-inducible gene therapy; 6. Multi-modality of breast imaging correlating SPECT/CT to mammography, MRI, and ultrasound. 7. Correlation of tumor oxygenation measured by MRI/EPRI and perfusion imaged by SPECT/CT; 8. Assessing the severity and response to treatment of acute lung injury The proposed acquisition will establish a new pillar in the unique integrated offering of SPECT/PET/CT, MRI/MRS, EPRI, and optical imaging/ultrasound for functional and molecular imaging in biomedical research at The University of Chicago. Our innovative methods for image reconstruction and processing will provide significant improvements in SPECT and CT image quality and quantitative accuracy, which can lead to novel use of the new system. Employing SPECT/CT imaging in investigation of tissue injuries and repairs, gene therapy, SERMs, bone cancer, breast cancer, lung injury, as well as other applications, will demonstrate how SPECT/CT can improve diagnosis of diseases, monitoring of treatment, and development of new drugs and therapies. With initial supplemental support from the Department of Radiology, the Dean's Office, the Cancer Research Center, and other units from the Biological Sciences Division and Pritzker School of Medicine, this hybrid microCT/microSPECT facility is expected to be self-sufficient in its routine operation in the near future. [unreadable] [unreadable] [unreadable]